Light-sensitive materials having a silver halide emulsion layer on one side of a support and a backing layer on the other side thereof (hereinafter often "one-side light-sensitive material"), which have the composition not identical on each side, tend to cause curvature in the light-sensitive material. There are some disadvantages accompanying the curvature, and what is important, for example, is that it tends to cause carrying troubles when a light-sensitive material is carried with an automatic carrying device.
It also often occurs that the degree of curvature (hereinafter often referred to as "the degree of curl") varies depending on conditions. For example, changes in temperature or humidity cause the curvature in various ways because of the difference in the layer constitution on both sides of the one-side light-sensitive material, thus resulting in variation of the degree of curl. The variation of the degree of curl makes it more difficult to take a coutermeasure to the curvature.
On the other hand, light-sensitive silver halide photographic materials should preferably be feasible for rapid processing. Since, however, the one-side light-sensitive material is comprised of a light-sentive emulsion layer formed only on its one side, the amount of silver (or silver weight) on one side must be made larger in many instances when compared with the case when silver halide emulsion layers are formed on both sides. In such instances, it follows that the amount of hydrophilic colloids in the emulsion layer must also be made larger, resulting in a poorness in drying properties when processing is carried out. This brings about a disadvantage in carrying out the rapid processing.
For improving the drying properties, it is preferred to make smaller the amount of hydrophilic colloids in regard to the silver halide emulsion layer and also increase the degree of hardening to lower the water absorption properties of the emulsion layer. Taking only such measures, however, may cause a deterioration of photographic performance, for example, an increase in fog, a lowering of graininess, or a poorness in scratch resistance.
As previously mentioned, it is also desirable for the light-sensitive material to have a small variation in the degree of curl against changes in temperature and humidity. For this purpose, what is important is the balance of layer thickness between the backing layer and emulsion layer, and it may be commonly attempted to make large the thickness of the backing layer to take the balance. A large thickness of the backing layer, too, results in an increase in water-absorption to cause defective drying. This consequently goes against the demand for rapid processing.
As mentioned in the above, there are a demand for the prevention of curvature (and variation of the degree of curl) and a demand for rapid processing with regard to the one-side light-sensitive material. It, however, is difficult to satisfy the both.
As pointed out in the above, the one-side light-sensitive material has a large silver weight on one side of a support, and in some instances the one side is coated with a silver halide emulsion in such a large silver weight that corresponds to the total silver weight on both sides of a both-side light-sensitive material. Such a large weight of silver present on the one side may make it impossible to sufficiently carry out fixing when the processing is made under rapid processing, resulting in a large quantity of remaining silver salts. As a result, the storage stability may be worsened, often causing a deterioration of the image quality during the storage of images obtained by the processing.
This problem can be solved by making small the silver weight on the emulsion layer side. Making small the silver weight on the emulsion layer side, however, may often cause other problems.
As an important problem, there is the problem that the decrease in the silver weight makes it difficult to detect a light-sensitive material.
For example, in CRT photography in which an infrared sensor detects a light-sensitive material used for photography, the sensor can not achieve the detection it the silver weight is small, so that all the operations after the detection, for example, carriage of the light-sensitive material, can not be performed.
Of course, the silver weight may be increased to solve such a problem in the detection, but this may cause difficulties such as defective fixing, which go against the fundamental demand of achieving rapid processing.